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Organization and Summary of Significant Accounting Policies (Property, Equipment and Furnishings and Restricted Cash) (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017
Restricted Cash |  |
Security deposits | $ 28,047 | $ 25,302
Minimum |  |
Property, Equipment and Furnishings |  |
Useful life of property, equipment and furnishings | 3 years |
Maximum |  |
Property, Equipment and Furnishings |  |
Useful life of property, equipment and furnishings | 39 years |
Parent Company [Member] |  |
Restricted Cash |  |
Security deposits | $ 10,692 | $ 17,795
WEST III |  |
Restricted Cash |  |
Minimum amount of cash from maintenance reserve payments required to be held in restricted cash account | $ 10,000 |
Projected maintenance obligation period | 9 months |
Projected maintenance obligation period for security deposit | 4 months |
WEST III | Minimum |  |
Restricted Cash |  |
Security deposits | $ 1,000 |
Willis Engine Securitization Trust II [Member] |  |
Restricted Cash |  |
Minimum amount of cash from maintenance reserve payments required to be held in restricted cash account | $ 9,000 |
Projected maintenance obligation period | 6 months |

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
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- Definition This element represents money paid in advance to protect the provider of a product or service, such as a lessor, against damage or nonpayment by the buyer or tenant (lessee) during the term of the agreement. Such damages may include physical damage to the property, theft of property, and other contractual breaches. Security deposits held may be interest or noninterest bearing. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.15(a)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
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- Definition Represents the maintenance obligation period for which cash reserve payments are held in the restricted cash account for the purpose of security deposit. + References No definition available. + Details
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